Osi san francisco



Mm!! 19 1929 Uw. N. DAvls ET A1. 1,705,809

PROCESS OF REHOV-ING SULPHUR COMPOUNDS FRQM PETROLEUM OILS @riginal Filed Oct. 15, 1924 widow Patented Mar. 19, i929.

ritrae srares Maagd@ A'fid'l @FFQL WILLIAM N. DAVIS, 0F OAKLAND, 'AND WILLIAM H. EAMETON, OF BERKELEY, AND

vIilDW'IN N. KLEMGARD, 0F ALBANY, CALIFORNIA, ASSIGNORS, :BY MESNE ASSGN- MENTS, TO STANDARD lOIL CoMlANY OF CALIFOl-NA, OF SAN FRANCESCO, CALI- FORNIA, A CORPORATION OF DELANABJE.

PROCESS OF REMOVING SULPl-IUR COMIPOUNDS FROM PETROLEUM OLS.

Application filed October 15, 1924, Serial No. 743,681. Renewed June 2, 192.8.

This invention relates to a process of removing sulphur bodies from petroleumoils and refers particularly to a process of treatpetroleum oils for preparation of gasoline or motor fuel. n

The greater portion of those petroleum oils that are now used in cracking .processes for obtaining naphtha or motor fuels are high yin sulphur content. kThe resulting naphtha or motor fuel prepared from .such oils is as a consequence also high in vsulphur bodies' and much ditiiculty has been encountered in developing a method for treating this product to remove the sulphun bodies.

The method that has been most` generally employed for this purpose isto treat Athe naphtha or gasoline with sulphuric acid at ordinary or roomtemperatures. The sulphuric acid employed has been 66,0 B. acid and While by such methods it is possible to obtain a motor fuel with a considerably7 reduced sulphur content by a steam distillation ofthe treated naphtha, such a process involves a large lossk of the hydrocarbons having boiling points Within the gasoline range. This loss of the desired boiling point gasoline is dueto the polymerizing action of the sulphuric acid on the unsaturated 4bodies Which polymerize to form hydrocarbons of higher molecular lWeight and boiling point and thus are removed fromboillng point range of g'asoline.-v The removal ofthe Y sulphur bodies by this customary treatment is also due tothe polymerization of the sulphur -bodies to higher Vboiling point oil sol'- uble constituents which therefor do not pass over upon-'steam distillation of the treated oil. lt is therefore apparent that the present method of removing sulphur bodiesby treatment vvith sulph'uric acid at ordinaryV ltemperatures involves a polymerization of the sulphur bodies Which goes. hand in hand with the polymerization of unsaturated hydrocarbons of the oil Which are desirablein the inished gasoline and'cOnseqLient-ly the present treatment involves an `lundesirable loss. l f l. 'y

An objectV of the present Vinvention is to `providea process of removingzthe sulphur .bodies -in such naphtha or motor fuel which can be carriedout Without any accompanying polymerization of such unsaturated hysolution or forming a loose chemical combination with the same, in place of theV polymerizing actionr involved inthe present process of removing such sulphur bodies,4 so thatv upon separationof the acid from the oil the sulphur bodies are removed Without any substantial removal of unsaturated hydrocarbons which are desired in the gasoline. vWe have also discovered that the rev moval of sulphur bodies by a solvent action at low temepratures 1s most effectively accomplished by strong sulphuric acid such,

for example, as sulphuric acid greater than v97% in strength and that particularly fumanother increases With temperature, the action .here discovered acts in the opposite manner, the increase in solubility undoubt- .edly being' due to the formation of certain loose chemical compoundsbetvveen the suling sulphuric acids, such as about 15% fumy phur bodies and acid, which are stable at loW u temperatures but either do not form or. de-Y compose at higher temperatures, such as room temperature, or above.

Other objects and advantages of the present invention-.Will be apparent from a description of the preferred process or'proccsses embodying the invention. esses will be more readily understood from the following description of the accompanying. drawings, in Which there is diagram-l matically indicated apparatus suitable for carrying out such processes.

In the drawings: K f l Figl is a diagrammatical View of an apparatus suitable for the v,treatment-of oils Such procto remove sulphur bodies at reduced teinperatures by a. batch method.

Fig.` 2 is a diagrammatical view of an apparatus for treatment of oils to remove sulphur bodies at reduced temperatures by the use of a continuous countertlow method of treatment.

Referring first to Fig. 1, 1 indicates a storage vessel for the naphtha, motor fuel or other petroleum oil which is to be treated. 2 indicates a pump (flesigued to draw the naphtha from the vessel 1 through the line 3 and force the same through a heat exchanger 4 and refrigerating coil 5 through a mixing device 14 into treaters 6 and 7 and the line 3 being connected through a line 8 controlled by a valve 9 to the vessel 6 and connected also by a line 9EL controlled by a valve 10 lto the vessel 7 so that the naphtha to be treated may be forced by the pump 2 selectively into either treater 6 or 7. The refrigerating coil 5 ymay be cooled by any of the generally known methods of refrigeration, such as a compressionv machine including a compressor 11 adapted to compress such substance as ammonia, sulphur dioxide, carbon dioxide, or the like, and thus liquefy the same by passing the same through the coil 12 cooled by any suitable means, and then permitted to expand in the neighborhood of the refrigerating coil 5 in order to reduce the temperature of crude naphtha passing therethrough.

15 indicates a storage vessel for the treating agent Which is connected by a line 16 to a pump 17 adapted to draw the treating agent from the vessel 15 and force the same into the mixing device 14 Where the treating agent passes, together With the crude naphtha, into either the treater 6 or the treater 7. The mixing device 14 is indicated as a vessel provided with suitable battles 18 for securing contact between the crude naphtha and treating agent rprior to their introduction into the treater 6 or 7. The line 16 leading from the storage vessel 15` is indicated as preferably passing through a sludge heat exchanger 19. Each of the treaters 6 yand `7 is provided With a line 20 connected at their lower ends, which lines 20 lead to ysludge circulating pumps 21 discharging again into the treaters near the top of the treaters, so that the mixture in the treaters 6 and 7 may be circulated through the lines 20 by pump 21 out and back into the'vessel to thoroughly agitate the naphtha With the treating agent. rlhe lines 20 also connect With lines 21EL controlled by valves 22 through which sludge separated in the treat-l ers may be drawn off and passed through aline 23 leading through sludge heat cxchanger 1.9 to storage tank 13.

Each of thel treaters 6 and 7 is also provided vvith la 'syvingpipe 24 by which the treated naphtha may be drawn off and passed through lines 25 controlled by valves 26 into a line 27 passing through the naphtha heat exchanger 4 into a treated naphtha tank 28, the line 27 being provided with a suitable pump 29. l

lilith such an apparatus the process :is preferably conducted as follows: The fresh or crude naphtha in the vessel 1 ispumped through vline 3 through the naphtha heat ex-` changer 4 and .refrigcrating coil 5 into the mixer 14 and hence to one of the treaters 6 or 7. During such time the treated naphtha from the other treater 6 or 7 is simultaneously Withdrawn through the line 27 andY passed through the naphtha heat exchanger 4 in order that the crude naphtha to be treated may be partially cooled from the treated naphtha passing through the storage vessel 28. In the refrigerating coil 5 the temperature of the crude naphtha is reduced. The temperature found most favorable for the cold treatment'is between 15 and 20o F. although it is not intended to limit the temperature of the treatment to Within such range, the best temperature of treatment may vary with changes of other conditions of the process. ing` agent is 15% fuming sulphurie acid, this acid freezes at 14 F. and hence therhest treatment, as previously stated, is between 15 and 20 F. The higher temperature employed, the greater Will be the undesired polymerization of the unsaturated constituents of the crudenaphtha andy hence the treating loss be increased. VIn the before-described apparatus, it is preferable to cool the crude naphtha to around 10O F. in. the coil5 as the treating agent vvill'raiseslightly the` temperature of the mixture before it passes into the treaters. Simultaneously with the passing of the crude naphtha into the treaters, the treating agent is drawn by pump 17 so as to flow through treating device 14 together with the crude naphtha. There is also drawn the spent treating agent fromA the previous treatment through theline 23l` When, as preferred, the treatand heat exchanger 19 inv order to vcool thel v fresh treating agent passing to the mixing device 14. As previously pointed out, Vthe preferred treating agent is concentrated sulphuric acid such as 15% fuming acid, although it is not'y desired to limit the invention to suchA treating agent but to include generally such equivalent'agents as are capable yof removing sulphur bodies from the naphtha by solvent action at reduced temperatures. AIn the treater 6 or 7 the charge'so introduced will be circulated by action ofthe pump 21 4to secure thorough contact betweenthe treating agent and naphtha. 'In certain cases it may be desirable to employ cooling coils in the treaters 6 and 7 to prevent the temperature iso Fig. 2, indicates a storage vessel for the crude naphtha to bc treated. 31 indicates a `line leading from the storage vessel 30 first through a naphtha heat exchanger 32 and hence through a refrigerating system 33 to a pump 34 adapted to draw the crude naphtha from the tank 30 and pass thesame through a line 35 into a treating vessel 36 the line 35 preferably communicating with. the treating vessel 36 near the center of the vessel. From the top of the'vessel 36 leads a line 37 which connects with a pump 38 adapted to draw naphtha from the treating vessel 36 and pass the same through a line 39 connecting with a. treating vessel 40 near its center, 41 indicates a line leading-from A. the top of the treating vessel and connected with a mixing device42 in turn connected by line 43 with the center of a treating vessel 44. 45 indicates a line leading from the upper end of the treating vessel 44 through the naphtha heat exchanger 32 to a storage vessel 46 for the treated naphtha.

47 indicates a storage vessel for the acid or other solvent treating agent to rbe ern- ,ployed, the vessel 47 being connected by a line 48 through a sludge heat exchanger 49 to a pump'50, the outlet end of which is connected by a line 51 to the mixing device 42 in order that the treating agent may pass together with the material from line 41 through the'mixing device and first into the center of the treating vessel 44. The bottom of the treating vessel 44 is connected by a line 52 controlled by the valve 53 with the inlet end of the pump 38. The bottom of the treater 40 is connected by a line 54 with both a line 55 controlled by a valve 56 and connected to the inlet end of the pump 38 and to a line 57 controlled by. a valve 58 to vthe inlet end of the pump 34. AThe treating vessel 36 is connected at its lower end by a line 59 connected both vbya line 60 controlled by a valve 61 with the inlet end of the pump 34 and by a line 62 controlled by a valve 63 with the sludge heat exchanger 49 from which the line leads to a spent treating agent storage vessel 64. l

The process as carried out in the vcontinuous apparatus is as follows: The crude naphtha is continuously passed from the storage vessel 3() through the heat exchanger 32 and refrigerating coil 33 into the treating vessel 36 entering near the center. Above the point at which the line 35 enters the vessel the crude naphtha will settle from the sludge supplied thereto and is continuously drawn oit through the line 37 and passed vthrough pump 38 `into thecenter of treating vessel 40. Likewise the naphtha is "then drawn from the top of the-vessel 40 and' passed through the line 41 through the mixing device 42 into the center of the treating Vvessel 44. From the top of the'treating vessel 44 thenaphtha is withdrawn through the Vline 45 and passes through the heat eX- changer 32 to the storage vessel 46. Thetreating agent passes through vthe sludge heat exchanger 49 into the vmixing device 42 where it is mixed with the naphtha passing through line 43 'to the vessel 44. It will thus be seen that the fresh agent comes in contact with the most treated naphtha.

ln the vessel 44 the acid settles to the bottom where it is drawn off through line 52 and passes, together with the naphtha in line 37 into the inlet end of the pump 38 from which the mixed naphtha and treating agent pass into the centerof the treater 40. In the treater 40 the treating agent settles to the bottom of the vessel where it is drawn off through the line 54. Preferably part of this agent is passed through line 55 into inlet end of pump 38 in order that part of the agent may be recirculated through the vessel 40.v The remainder of the acid passes through a line 57 through the pump 34 entering together with the fresh naphtha into the center of the treating vessel 36. It is through line 60 and pump 34 back into the vessel 36 and the remainder is drawn through line 62 through the sludge heat exchanger 49 into the storage vessel 64. l v

The temperature to which the naphtha agent mixture is reduced is preferably the same as in the previous described process.

By the processes of this invention crude naphtha may be treated for the removal of sulphur bodies with the minimum polymerization of the unsaturated bodies desired in the finished naphtha and thus the treating loss substantially reduced. Vxhile the treatment is particularly useful upon naphtha obtained from a cracking process it is not intended to limit the invention to the treatment of such naphtha as it may also be applicable for treating Voils such as shale oil, etc., which are high in sulphur content andcontain a large percentage of unsaturated bodies.

. The process is of a particular value in the treatment of, cracked dlstillates. To effect efficiently the removal of sulphur bodies Vconstituents which will be readily attacked by the acid, unless these low temperatures are employed, with the result that the unsaturated materialwould be polymerized and removedfrom the finished product and thus'the saving of these bodies not effected.`

60% filming l Insel l l While the processes herein described are well adapted to aeeon'iplish the purposes ot this invention, various moditications .may be madewithout departing from the spirit ot' the invention. rlhe invention is of the scope setforth in the appended claims.

To claim:

l. rllhe process of treating` petroleum loils which comprises cooling the oils beloW 200 F. and contacting the oils with turning sulphurie acid.

2. The process of treating petroleunroils for the removal oitlk sulphur bodies `substantially Without polymerizing the'unsaturated constituents of the oils Which includes substantially cooling the oils and contacting` the same at a temperature below 200 F. With t'uming sulphuric aeid containing between 5 and sulphuric anhydrid.

3. In a process of treating' cracked pet-reg leuni naplitha and similar high sulphur petroleum distillates with sulphurie acid to remove sulphur bodies, substantially reducing the polymerization of unsulphured bodies by treating` the oil at below 38F. with an acid olf lowertreezing,` point than the reaction temperature.

4t. In a process of treating` cracked petroleum naphtha and similar high sulphur petroleum. distillates With sulphuric acid to remove sulphur bodies, substantially reducing the polymerization of unsulphured bodies by cooling the oil to below 380 F. and treat# ingthe cool oil with an acid of lower freesu ingpoint than the reaction temperature.

In a process ot treating cracked petroleum naphtha. and similar high sulphur betroleuin distillates With sulnhuric acidv to remove sulphur bodies, substantially reducing the polymerization of unsulphured bodies by continuously cooling the oil to below 380 F., continuously passing the cool oil countereurrent to an acid oil. loWer freezing,` point than the reaction temperature to Y WILLIAM N.r DAVIS.

WILLIAM n. HAMPTON. EDWIN N. KLEMGARD. 

